The invention relates to computer terminals, and particularly to PC board cartridges for computer terminals.
Today's smarter computer terminals sometimes support optional features requiring a user-installed expanded memory option. One way of supporting such an option is by providing a PC board cartridge. The cartridge is an assembly including a PC board containing the memory which the user plugs into the terminal. Since the option is user installed, safety and ease of installation are important considerations in cartridge design as is maintaining the integrity of the memory connection to the terminal.
In the past, such user-installed memory options have been provided for terminals such as the VT340 from Digital Equipment Corporation. The VT340 memory cartridge included a molded plastic enclosure for holding a PC board including a ROM chip. The PC board included a vertical male edge connector to be received by a vertical female edge connector upon installation into the terminal. The cartridge included a handle for removal, the handle being an elongated member hinged at a single point at the top of the cartridge. The user removed the cartridge by rotating the handle outward from the terminal and pulling until the mating connector pairs disengaged.
This particular cartridge design had a number of problems. First of all, the only means of securing the cartridge to the terminal was the frictional contact of the connector itself, resulting in undesirable stresses on the connector. Secondly, the mating pairs of an assembled connector should be disconnected using a force substantially parallel to the connector pins in order to preserve connector integrity. However, the removal point of action of the handle for the VT340 cartridge acted at the top edge of the connector, causing the connector to rotate as it disconnected. There is a need for an improved user installed PC board cartridge which maintains connector integrity while providing ease of installation and removal for the user.